This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. A fundamental problem in biology is to understand how cells are able to sense and respond to environment cues. The integration of chemical signals such as growth factors and cytokines with mechanical stimuli is not well understood. The place where cascades involved in solid-state (mechanical) signaling and soluble (chemical) signaling converge and the manner in which they interact is no doubt complex. This research project is designed to investigate signaling events associated with both chemical and mechanical stimuli. Cells of the vascular system are continuously exposed to the effects of mechanical forces such as stretching and fluid shear stress. These forces, which are created by the pulsatile nature of blood flow when the heart contracts and relaxes, have a marked influence on cell structure and function. The adaptations of these cells, including enhanced growth and migration, seem to be important in the pathological conditions that accompany cardiovascular diseases such as atherosclerosis, hypertension, and restenosis. Cardiovascular disease remains a major cause of morbidity and mortality in the U.S. and the economic and human costs associated with these pathologies are enormous. This has resulted in an intense research interest in the mechanisms which regulate contraction, migration, and growth of vascular smooth muscle cells (VSMC). While it is now clear that mechanical forces imposed on cells of the vessel wall are important factors in the initiation and progression of pathological changes, the molecular mechanisms involved in these adaptations are not fully understood. In addition, it is now clear that the basic mechanism of smooth muscle contraction can only be explained in light of actin remodeling. However, the exact nature of cytoskeletal reorganization and the mechanisms regulating these changes are not well known. The overall goal of this project is to elucidate the acute responses in cytoskeletal reorganization that occur during mechanical stress of VSMC and to determine the intracellular signaling mechanisms that are involved. Utilizing molecular approaches combined with fluorescence microscopy, and relying on the precise changes in cell orientation and actin cytoskeletal reorganization as endpoints for quantitative assessment of responsiveness to mechanical strain, we will evaluate the role of various cytoskeletal structures on the response of VSMC to stretch. Further, we will make a systematic determination of the effects of various types of mechanical stress on activation of cell signaling molecules. In addition, we will evaluate the effects of resveratrol, a purported cardioprotective molecule, for its potential effects on stretch-induced cell signaling and receptor mediated cellular hypertrophy. The use of pharmacologic and molecular techniques to stabilize, destabilize or down-regulate specific cytoskeletal components is expected to provide clear answers concerning the role of specific components in mechanotransduction and the cell orientation response. The inhibition or down-regulation of specific signaling proteins is expected to provide information concerning pathways regulating mechanosensing and transduction. The knowledge gained may be useful in the development of therapeutic agents regulating mechanotransduction mechanisms contributing to cardiovascular pathologies.